Production of liverstock feed from sugarcane

ABSTRACT

A process for sustaining livestock, e.g., ruminants such as cattle, is described which involves providing the livestock with a feed comprising sugarcane pith which contains a substantial amount of the naturally present sugar juice and which is substantially free from the highly lignified outer rind fibers of the sugarcane. This feed may also contain nitrogenous protein substituents such as urea, a leguminous meal, and various minerals. The sugarcane pith may be obtained by longitudinally opening sugarcane without expressing a significant amount of the sugar juice from the pith, and then separating the pith from the outer rind fibers while retaining substantially all of the sugar juice in the pith.

United States Patent 1191 Miller et al.

]March 20, 1973 Assignee: Canadian Cane Equipment Ltd.,

Montreal, Quebec, Canada Filed: A riliTiti I Appl. No.: 26,598

U.S. Cl. ..99/2 ND,-l27/42 Int. Cl. ..A23k 1/18, A23k l/22 Field of Search ..99/2 R, 6, 141, 9.8 E

References Cited UNITED STATES PATENTS 11/1965 Taylor ..99/2 707,113 8/1902 Hughes.....

OTHER PUBLICATIONS C. C. Culbertson, Feed Urea in Ruminant Nutrition, No. 348, July 1953.

S. H. Work, Feed Urea in Ruminant Nutrition, No. 174, May 1943.

Primary Examiner-Norman. Yudkofi Assistant Examiner-C. R. Bando Attorney-Burns, Doane, Swecker & Mathis [5 7] ABSTRACT A process for sustaining livestock, e.g., ruminants such as cattle, is described which involves providing the livestock with a feed comprising sugarcane pith which contains a' substantial amount of the naturally present sugar juice and which is substantially free from the highly lignified outer rind fibers of the sugarcane. This feed may also contain nitrogenous protein substituents such as urea, aleguminous meal, and various minerals. The. sugarcane pith may be obtained by longitudinally opening sugarcane without expressing a significant amount of the sugar juice, from the pith, and then separating the pith from the outer rind fibers while retaining substantially all of the sugar juice in the pith.

4 Claims, 1 Drawing Figure PATENTEDHA RZOIQH 3,721,567

INVENTORS ROBERT B MILLER C. KEITH LAURlE A TORNEYS PRODUCTION OF LIVERSTOCK FEED FROM SUGARCANE BACKGROUND OF THE INVENTION Field of the Invention This invention relates to the manufacture and use of feed for livestock. More particularly, the present invention relates to a novel composition containing sugarcane pith for use as livestock feed and to processes for the preparation and use thereof.

Introduction To feed the burgeoning world population, it is of importance that the efficiency of food production systems be improved through more efficient use of existing facilities, introduction of new types of crops and livestock, and development of new feed processing techniques.

Present trends of feeding livestock which are used for human food production are of concern because of the direct competition between feed for livestock and food for man, as illustrated by the large amounts of grain usually incorporated in livestock rations. Despite this competition, there is an almost indispensable place for livestock agriculture in the overall pattern of food production. Whereas in some instances, livestock do seriously compete with man, in many others they may not. This latter situation is exemplified by herbivorous animals, particularly ruminants, such as cattle, which possess digestive abilities that man does not.

' A digestive characteristic ofruminants, which sets them apart from man, is their ability to digest cellulose. Critical to this ability is the presence of a multicompartment complex stomach which through the presence of various micro-organisms hydrolyzes the chemical linkages of cellulose eventually producing energy and releasing plant cellular components which are also utilized by the animal.

Cellulose is the structural component of all plant cells and is the most widely distributed single organic compound in the plant kingdom. Dispite this abundance, only herbivorous animals, particularly ruminants, can utilize cellulose as a source of energy, since other species do not possess digestive facilities for the degradation of cellulose. Cellulase, the enzyme responsible for this degradation, is produced by microorganisms which reside in the complex stomach of ruminants. The volatile fatty acids produced by these micro-organisms serve as the actual energy source for the host animal.

In the tropics, competition between man and livestock for food is not as severe as in temperate countries because the cereals have been grown essentially for human consumption and livestock such as cattle have been left to procure their requirements from other sources, including whole sugarcanes and sugarcane byproducts.

Sugarcane, a giant member of the grass family, is

widely grown in tropical countries for the production of sugar, mainly for export. This crop provides one of the cheapest forms of energy food, with the lowest unit of land area required per unit of energy produced. Although sugar does not provide a complete diet for man, it represents about one seventh of his total energy intake. As an efficient energy producer, it has been estimated that the energy produced by one acre under sugarcane is equivalent to that produced by seven acres under wheat, twenty acres under milk production and over one hundred acres under beef production. Despite the energy potential of sugarcane, however, its use in livestock feed has not been widely advocated and past attempts to utilize sugarcane and sugarcane byproducts in livestock feed have been somewhat unsuccessful.

Summary of the Prior Art Whole mature sugarcanes have been used in limited amounts for feeding to cattle. However, due to the high lignin content substantially increasing the rigidity of the outer rind, the digestive tractof the ruminant may be seriously harmed, e.g., punctured, by the sharp coarse nature of whole sugarcane stalks. Sugarcane tops have also been consumed by draft animals in the sugarcane fields, but the efficiency of their utilization is questionable owing to the coarse nature of the material which may also cause physical damage to the digestive tract of the animal.

Bagasse, the coarse fibrous residue of certain sugarcane juice extraction processes, is primarily used at the sugar factory as fuel for plant operations. Depending on the efficiency of the crushing operation, bagasse may vary in its content of sugars, although in any event,

such sugars represent a relatively small fraction of the bagasse. To livestock, bagasse is an unpalatable feedstuff when used alone but intake and energy content have been increased by the addition of molasses, another of the sugarcane by-products. Bagasse utilization by livestock is primarily limited by its high content of highly lignified material, e.g., the hard outer rind fibers, which disrupts the digestive systems of the livestock. Further, investigations have shown that it takes more energy to digest the bagasse than is obtained from it by the livestock.

Bagasse pith, another sugarcane by-product, is obtained by expressing the sugar juice from the sugarcane and screening out the hard outer rind fibers. Again, because it may take more energy to digest bagasse pith than is obtained from it, molasses has been mixed in with the bagasse pith. See, for example, US. Pat. No. 707,113.

Whether sugarcane or sugarcane by-products be used, additional nitrogenous ingredients are usually added to the feed as supplementary protein substituents, urea being the most common nitrogenous protein substitute used. A drawback, however, is that urea has been found to have a toxic effect on livestock where too high a proportion is used in the feed.

SUMMARY OF THE INVENTION Accordingly, a primary object of the present invention is to provide an improved livestock feed from sugarcane which feed substantially prevents or alleviates one or more of the disadvantages of the prior art as discussed above.

Another object is to provide a process for sustaining livestock with a feed composition which has a high energy content and is adequate as a sole dietary constituent, which is highly palatable, and which is easily digestible.

A further object is to provide a livestock composition which allows higher levels of urea to be incorporated therein without toxic effects on the livestock.

A further object is to provide a process for preparing such livestock compositions from sugarcane.

These and other objects of the present invention will become apparent with reference to the following summary of the invention and the description of preferred embodiments thereof:

According to the present invention, a process is provided for sustaining livestock which involves providing or supplying the livestock with a feed composition comprising'sugarcane pith which contains a substantial amount of the naturally present sugar juice, i.e., a substantial amount of the sugar juice originally occurring in the pith is retained in the pith. Further, this sugarcane pith is substantially free from the highly lignified outer rind fibers of the sugarcane and is not disruptive of the digestive systems of livestock.

In another aspect of the present invention, this sugarcane pith is combined or mixed with nitrogenous protein substitutes such as urea to provide an even better feed. Surprisingly, it has been found that nitrogenous protein substitutes such as urea may be mixed with the sugarcane pith in higher proportions than in previous feeds without toxic effects on the livestock.

In yet another aspect of the present invention, a process is provided for preparing or producing livestock feed compositions from sugarcane comprising longitudinally opening or splitting the sugarcane stalk without expressing a significant amount of sugar juice from the pith, separating the pith from the highly lig nified outer rind or rind fibers while retaining substantially all of the sugar juice in the pith, and then adding to the separated pith a nitrogenous protein substitute such as urea.

These and other aspects and advantages of the present invention will be more fully appreciated in view of the following description of the preferred embodiments and the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING The drawing pictorially illustrates a section of sugarcane and its various components.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The drawing shows a typical section of sugarcane stalk. This portion of the stalk has two modes 12, the part therebetween being an internode. The outer rind fiber region 14 of the internode is hard, highly lignified, and is comprised primarily of interconnected fibrovascular bundles. A thin epidermis, mostly thin, fine fibers, covers the rind and clings loosely to the stronger and larger fibrovascular bundles. The interior 15 of the stalk is mainly soft pith that contains most of the sweet natural sugar juice. The exterior of the mature internode is usually covered with a thin film of waxy bloom or cutical wax, as it is frequently called. Wax is also found throughout the rind as well as on the surface. A ring 16 beneath the node 12 contains a high concentration of wax. A band 17 above the wax ring 16 is called the leaf scar. A root band 18 is a small section of the node just above the leaf scar 17 that usually differs in color from the internode and has many small clots. Under favorable moisture conditions, a root may develop at each dot, should the section of stalk 10 be placed in the ground. Just above the root band 18, and not usually clearly distinct from it is a transition area known as the growth ring 19. Elongation and growth of the internode takes place in this area. A bud 20, when exposed to favorable moisture and temperature conditions and with proper stimulus, can develop into a new shoot. Expansion of the diameter of the stalk 10 may result in growth cracks 21 which may extend inwardly through the rind. Smaller barely distinct, corky cracks i may develop along the internode and separate the fibrous material of the rind for short distances.

The particular composition of sugarcane may vary according to the particular species, as well as soil con ditions, climate, and modes of cultivation. For example, sugarcane stalk may average from about 8 to 16 percent dry fiber and from 84 to 92 percent water and soluble solids (mostly sugars). Further, the pith may constitute from to percent of the cane stalk and may contain about 16 to 18 percent sugars (mostly sucrose, with some glucose and fructose).

As stated above, the separated sugarcane pith utilized in the present invention contains a substantial amount of naturally present sugar juice and is substantially or essentially free from highly lignified outer rind fibers.

Preferably, the separated sugarcane pith has retained enough of the sugar juice such that the pith comprises above about 10 percent sugars. Most preferably, the sugarcane pith contains substantially all of its original sugar juice. When stored over a period of time, the separated pith may lose some of its water content due to evaporation and some of its sugar content due to chemical decomposition. These losses, however, are normally negligible with respect to the function of the pith as a feed for livestock.

The sugarcane pith utilized in the present invention is preferably separated from the hard outer rind of the sugarcane stalkby longitudinally opening or splitting the stalk without expressing a significant amount of sugar juice from the pith, and thereafter separating the pith from the outer rind fibers while retaining substantially all of the sugar juice in the pith.

The splitting of the stalk and separation of the pith is preferably achieved using the methods and apparatus described in one or more of the following United States patents and patent applications, all of which are incorporated herein by reference: US Pat. Nos. 3,424,61 1, 3,424,612, 3,464,877 and 3,464,881; US. Patent applications Ser. No. 692,185, filed Dec. 20, 1967, Ser. No. 692,237, filed Dec. 20, 1967, and Ser. No. 714,896, filed Mar. 21, 1968 now US. Pat. Nos. 3,567,510, 3,566,944 and 3,567,511 respectively. As described therein, the splitting of the stalk and separation of the pith involves handling the sugarcane stalks individually rather than in bulk as is done in conventional whole cane milling operations where masses of randomly oriented sugarcane are delivered in bulk to massive machinery that cuts, crushes, shreds and breaks the whole cane stalk, and under high pressure forcefully squeezes out the natural sugar juices.

For example, the sugarcane pith utilized in the present invention may be obtained by positively feeding an aligned stalk against a stalk splitting or cutting edge which opens the stalk up longitudinally, and then brushing, scraping, scooping, or milling the pith away from the exposed inner portion or side of the split stalk. These operations are performed without any effective squeezing or compressing of the pith so that the sugar juice may be retained in the pith. The means or apparatus for performing these operations are not a part of the present invention and thus for sake of brevity are not described further herein. For a more detailed discussion of the separation process and apparatus, reference may be made to the above listed U.S. patents and patent applications.

Because of the high-energy content of the uncompressed sugarcane pith, it may be suitably used in accordance with the instant invention as the sole feed to sustain or maintain livestock, e.g., ruminants such as cattle and sheep.

Additional dietary supplements, however, may be added to the sugarcane pith to enhance its use as a livestock feed.

An example of a particular nutrient which may be added to the uncompressed sugarcane pith to increase the nutritive value of the pith in a livestock feed is a nitrogenous protein substitute which can be converted into protein by the livestock. That is, a limiting factor in the utilization of roughage by ruminants such as cattle may be an inadequate supply of nitrogen with which to satisfy the growth requirements of the microbial population of the ruminants complex stomach. Although many non-protein nitrogenous compounds may be used to fulfill this need, urea is most frequently used.

Cases of urea toxicity have been known to result where high concentrations of urea were used in the livestock feed ration. The present invention, however, allows higher levels of urea to be incorporated into the livestock feed than heretofore possible with no noticeable toxic or other adverse effect upon the animals involved. For example, urea may be incorporated into the feed in amounts of about 1 to 30 percent, preferably 1 to 20 percent, and most preferably about 5 to percent.

To supplement the urea which is ultimately converted into protein nitrogen, other protein supplements may be added to the livestock ration. For example, brewery by-products cotton-seed and coconut oil or legumes such as soybeans, clover, alfalfa, peas, peanuts. and beans, may be added as a meal or in some other suitable form, and in amounts of about 10 to 90 percent. preferably about 40 to 80 percent.

Mineral supplements may also be added to the livestock ration, for example, as salts in a dry mix to facilitate ease and convenience of handling and use. These mineral supplying salts may include necessary anions such as the chlorides, bromides. iodides, sulphates. phosphates, nitrates, carbonates and the like. of various elemental substances necessary to p omote proper growth and function. Similarly, the necessary metallic and non-metallic elements such as sodium. potassium, calcium, iron, copper, phosphorous, sulfur, nitrogen, and the like may also be added in an appropriate form. The mineral supplement may be present in the feed in amounts of about 5 to 50 percent. and preferably from 10 to 30 percent. For exa ple a suitable mineral mix may contain 10 to percent calcium, 5 to 10 percent phosphorous, to 50 percent sodium chloride, and from about .001 to 2 per cent iodine Additional nutrients which may be mixed with or added to the composition of the instant invention inrlude vitamins which are biochemically necessary to maintain growth and functioning of organic tissue. Particular vitamins include, among others, vitamin A, necessary to maintain the integrity of epithelial tissue,

' vitamin B, which aids in preventing pernicious anemia,

vitamin B riboflavin, thiamine, and vitamins C, D, and E, to name only a few.

Of course, other ingredients may be added to the livestock feed composition of the present invention to modify it without departing from the spirit and scope of the invention. For example, various liquid or semiliquid additives can be used to enable the feed to be pressed into pellets, bars, or cakes to facilitate handling. If desired, additional natural or artificial flavors may be added to further increase the palatability of the feed. Various other curative or preventive compounds or compositions may also be added to the feed, such as drugs or medicines in the form of powders, granules, tablets, or liquids of varying viscosity. Similarly, other compounds may also be added to or mixed with the feed to obtain desired effects on the livestock.

The invention is further illustrated by the following examples; all parts and percentages in the examples and throughout the specification are by weight unless otherwise indicated.

EXAMPLE I The following example was conducted at an altitude of approximately 1200 feet above sea level with the temperature during this period varying between an average minimum of 72 F and average maximum of 88 F. The average monthly rainfall was 5.28 inches with the highest 6.65 inches.

Six of the cattle used in this run were Senepol steers (derived from breeding Senegal and A Red Poll) which represent livestock with beef producing potential, cross-bred for tropical conditions. The Senepol Steers were in good condition at the beginning of the run and ranged in weight from 200 to 402 pounds. The remaining steers used in the run were Holstein and represent livestock essentially bred for milk production under tropical conditions. These Holstein steers were from 4 to 8 months old and weighed from to 206 pounds with a physical condition somewhat below that of the Senepol steers.

The steers used in run were housed individually to enable separate feeding and watering.

The first portion of the run involved an intensive feeding period consisting of 77 days. Two different rations were tested on the steers. Four steers of each breed were placed on a supplemented fresh sugarcane pith feed or ration, and two others were placed on a control consisting of a dairy ration and a citrus pulp ration. During these 77 days, the steers were penned separately and individually fed and watered. initially, the steers were fed once a day but during the last month of the period, the steers consuming the most feed were fed twice a day. The sugarcane pith leftover from the previous days feeding was always discarded. The weight of each steer was determined during the entire 77-day period.

The second phase of the run involved an extended feeding period of 21 days wherein the pen partitions in the livestock shelters were removed and the ten steers, i.e., the eight formerly on the sugarcane pith supplemented ration, plus the two Senepol steers formerly on the control ration, were group fed the sugarcane pith supplemented ration for the entire time. This extended feeding period was used to determine what effect individual versus group feeding might have on livestock performance. The steers were weighed at the beginning and the end of the 20-day interval although no data was collected on individual feed consumption during this period.

The sugarcane pith used in the supplemented feed ration was obtained daily from mature sugarcane stalks which normally would be used for sugar production. The stalks were first split down the middle into halves and each fed through a separator similar to that disclosed in U.S. Pat. application Ser. No. 692,185, filed Dec. 20, 1967, listed above. Using this particular method and apparatus, the pith was milled away from the split stalk portions and obtained with substantially all of the sugar juice originally contained therein and was in the form of a fluffy or flocculant mass free from the highly lignified outer rind fibers and any waxes.

A supplement of the following compositions was fed to the livestock at a rate of 2 pounds and 1 pound per animal per day to the Senepols and the Holsteins, respectively:

Percent Soybean Meal 67 (44% Protein) Urea 13 (42% Nitrogen X 6.25 262% Crude Protein) Mineral Mix 20 (Purina) The approximate composition of the mineral mix as noted by the manufacturer was substantially as follows: Calcium 13-15 Phosphorous (not less than) 6.5 Iodine (not less than) 0.0006 Sodium Chloride 40-45 A Vitamin A pre-mix (10.00 lntemational Units/gram) was added at a rate of 0.50 grams per 450 grams of supplement. The supplement was prepared fresh daily and mixed into the top one-third of the sugarcane pith which was fed ad libitum to the steers, i.e., the steers were fed as much sugarcane pith as they desired.

The control animals were fed a combination of a commercial dairy ration at 4 pounds per day and a dried citrus pulp which was fed ad libitum, i.e., as desired. The commercial dairy ration comprised 16 percent minimum crude protein including not more than 5 percent equivalent crude protein from urea, 2.3 percent minimum crude fat and 14 percent maximum crude fiber according to the manufacturers specification.

For the greater part of the period, the weights of the two largest Senepol steers were estimated with a calibrated tape measure (e.g., a Weight Band, distributed by Cooper, McDougall and Robertson, Ltd., Berkhamstead, Herts, England) because of their large size which precluded the use of a weighing scale. The body weight changes of the steers during the first 77- day period of the test are summarized in Table l and Table II. The body weight gain of the Senepol steers was almost twice the rate gain of the Holstein steers when fed the sugarcane pith supplemented ration. A

possible explanation for the difference in rates of gain between the two breeds might be attributed to the heavier initial weight of the Senepol steers as well as the reduced intake of ration by the Holstein steers (Table 1) and their generally poorer pre-trial condition.

TABLE I Sugarcane Pith Control Holstein Senepol Senepol Number of steers 4 4 2 Av. lnitial Wt. (lbs.) 181 277 301 Av. Final Wt. (lbs.) 236 383 340 Av. Total Gain (lbs) 55 106 39 Av. Daily Gain (lbs) 0.71 0.31 0.51 Daily Feed Consumed Sugarcane Pith, lbs. 16.4 25.2 Supplement, lbs. (as fed) 1.0 1.9 Citrus Pulp, lbs. (as fed) 3.0 Dairy Ration, lbs. (as fed) 3.4 Total (as fed) 17.4 27.1 6.4 Feed Efficiency (As Fed) 27.6 19.9 12.4

TABLE II Liveweight changes of steers during 77-day period (pounds) Steer initial Final Total Daily No. Ration Wt. Wt. Gain Gain S1 Sugarcane Pith 354 489 1.75 S2 Sugarcane Pith 234 318 84 1.09 S3 Sugarcane Pith 246 356 1 10 1.42 S4 Sugarcane Pith 274 370 96 1.25 S5 Control 200 208 8 0.10 S6 Control 402 472 70 0.91 H1 Sugarcane Pith 178 248 70 0.91 H2 Sugarcane Pith 208 38 0.49 H3 Sugarcane Pith 172 208 36 0.47 H4 Sugarcane Pith 206 282 76 0.98

1; Senepol steers 2,, Holstein steers Table 111 and Table IV illustrate the body weight changes of the animals during the second phase of the trial, i.e., the additional 2l-day period. Values show that steers fed the sugarcane pith supple-mented ration under feed-lot conditions achieved even higher rates of gain than when individually pen fed.

TABLE 111 Weight changes during additional 21-day period (pounds) 6-Senepols 4-Holsteins Av. Initial Wt. 369 236 (Aug. 3 1 st) Av. Final Wt. 407 254 (Sept. 20th) Av. Total Gain 38 18 Av. Daily Gain 1.81 0.86

TABLE IV Weight changes of steers on sugarcane pith ration over additional 2l-day feeding period S Senepol steers H Holstein steers For purposes of comparison, tropical cattle under grazing conditions, on good feed at the best time of year, generally realize satisfactory weight gains of approximately 0.75 pounds per day.

Thus, it can be seen that fresh sugarcane pith is very satisfactory when used in a ration as the main source of energy for livestock.

In summary, comparing the daily average weight gains made by the Senepol steers in both the 77-day and 2lday periods, with that obtained under existing systems of cattle rearing in the tropics, it can be seen that production on a sugarcane pith based ration is superior to that normally obtained.

EXAMPLE II This example was conducted under substantially the same climate conditions as Example I.

Eight mature indigenous male sheep weighing between 40 and 60 pounds were used in this example. The animals were kept in individual cages to enable total excrement collection and voluntary intake determinations.

The first phase of the run consisted of feeding the sheep the same composition as that fed to the steers'in Example I;-. namely, sugarcane pith and 200 grams of supplement fed ad libitum. The actual 7-day test period employed to obtain the desired values followed a fiveweek adaptation period wherein the animals were all fed the sugarcane pith ad libitum with an increasing supplement mix which eventually attained the 200 gram level. The second phase consisted of the ad libitum feeding of sugarcane pith and 100 grams of supplement to the test animal for 7 days. Immediately following a 7day adaptation period during which the animals were given time to accustom themselves to the dietary variation, the supplement level was reduced in the second phase of the run in order to determine whether the nutrients other than those supplying energy were limiting the utilization of the sugarcane pith. Digestibility and voluntary intake values for the ration were determined for both phases of the test.

The sugarcane pith and supplement were prepared as described in Example I, with the supplement mix for each" sheep pre-weighed and individually packaged. Both feed and water were constantly available to all of the sheep. Feed consumption was determined daily wherein the amount of feed available on each successive day was 10 percent in excess of the previous days consumption per animal. Feed samples were also chemically analyzed on a daily basis. Provisions were also made for collection of animal excrement daily during each of the 7-day test periods for chemical analysis. The animals were weighed before and after excrement collection to obtain data for calculating the Relative Intake of the ration. The sheep became adapted to their new environment and feed rather quickly and did not exhibit any ill effects during the trial.

Chemical analyses (Table V) were conducted for dry matter and crude protein content of both the feed and the excrement samples according to procedures of the Association of Official Agricultural Chemists (Official Methods of Analysis 10th Edition, 1965). The crude protein content was calculated after a determination of nitrogen by the Kjeldal method followed by multiplying III the value obtained by 6.25. The cellulose content of both the feed and the excrement was determined by a method as described by Donefer et al, Journal of Animal Science. 19, 545. An oxygen bomb calorimeter was used to determine the gross energy content of the feed and the excrement samples.

The chemical analysis of the feed used is below in Table V.

set forth TABLE V Chemical analysis of components of ration Dry Gross Energy Crude Ingredient Matter k.callgm Protein Cellulose Sugarcanev pith 91.9 4.25 1.5 l7 .5 Supplement mix 87.3 3.44 70.9 8.0

From Table V it may be noted that the cellulose content of the sugarcane pith is higher than that normally found in grain seeds, such as corn, barley, oats, etc.

The relatively low gross energy value of the supplement mix is a result of the addition of mineral components which are non-energy containing materials. The high crude protein content reflects the urea contained in the supplement which has the equivalent of over 250 percent crude protein. The value for the cellulose content is somewhat higher indicating a contribution by the soybean meal which contains about 10 percent cellulose.

The apparent digestibility coefficients of dry matter,

gross energy, crude protein and cellulose were calculated using the following formula:

Coefficient of digestibility o o) I OI/( O O) X 100 Relative Intake (Observed intake )/(W--", X

where (W is the metabolic body size of the animal which takes into account the animals weight. The Nutritive Value Index (NVl) for feeds is then calculated by multiplying the Relative Intake of the feed by its percent gross energy digestibility.

N.V.I. Relative Intake X gross energy digestibility,

Relative Intake (RI) is a measure of voluntary intake and is compared to that of standard high-quality forage. The Nutritive Value Index (NVI) is an index of feed nutritive value, which is the product of the relative intake and the gross energy digestibility of a particular feed composition. It is used as a measure of the digestible energy intake potential of the ration.

Values for the Apparent Digestibility of dry matter, gross energy, crude protein and cellulose, as well as Relative Intake and Nutritive Value Index, are summarized in Table VI.

TABLE VI Summary of apparent digestibility values, Relative Intake, and Nutritive Value Index of sugarcane pith supplemented ration fed to sheep Level of Supplementation 100 gm 200 gm Apparent Digestibility (17) Dry matter 77.2 77.6 Gross energy 76.1 76.8 Crude protein 71.8 80.8 Cellulose 57.l 59.6 Relative Intake 84.9 99.2 Nutritive Value Index 64.7 76.2

These values indicate that all the components under' investigation are adequately digested and that the metabolic utilization of the energy from the sugarcane pith was not limited by nutrient deficiency. The high value of cellulose digestibility if ofparticular interest in that it suggests the cellulose utilization was not appreciably limited by a lignin complex. Further, the Relative Intake Value of 99.2 observed for the sugarcane pith feed at the 200 gm. supplement level is essentially the same as that of high quality legume forage such as alfalfa or clover hay.

The slight increase in cellulose digestibility at higher supplementation levels may be attributed to increased microbial activity in the animals digestive system. This is based on the assumption that the increased nutrient contribution at a higher supplementation level may have acted as a stimulant to the micro-organisms responsible for cellulose degradation.

The availability of the gross energy of the sugarcane supplemented ration (approximately 75 percent is on the order of that observed for high-quality grain such as barley. It should be noted, however, that the digestibility values presented represent contributions by both the sugarcane pith and the supplement components of the ration. In spite of this, these energy values can be largely attributed to the sugarcane pith since it comprises approximately 85 percent of the entire ration. In fact, the energy availability of the sugarcane pith alone should be higher than that reported for the mixture since the supplement to which it is added would not be considered a good source of energy.

The weight gains of the sheep on each of the feeding schedules over the 7-day trail periods are tabulated in Table VII. The results indicate that the animals gained more on the higher level of supplementation. The results also indicate the effect of a superior nutrient contribution resulting in increased weight.

TABLE VII Live weight changes of sheep on rations over 7-day test periods Level of Supplementation 100 gm 200 gm Av. Total Gain (grams) 269 766 Av. Daily Gain (grams) 38.4 109.4

values represent average of eight sheep EXAM PLE III about 4 weeks feed ad libitum nothing but sugarcane pith. The pith was prepared as described in Example I except that no supplement whatsoever was used. The bull remained healthy and suffered no noticeable ill effects during the feeding period. When the bull was butchered, the digestive tract looked healthy and normal, with no signs of punctures or other ill effects.

The principles, preferred embodiments, and modes of operation of the present invention have been described in the foregoing specification. However, it should be understood that the invention which is intended to-be protected herein may be practiced otherwise -than as described without departing from the scope of the appended claims.

What is claimed is:

l. A process for producing livestock feed from sugarcane, the sugarcane having as components a highly lignified outer rind region including outer rind fibers, epidermis and wax covering the outer rind region, and an interior of pith containing naturally present sugarjuice, which process comprises:

a. splitting sugarcane stalk parallel to a longitudinal axis of the stalk while retaining substantially all of the naturally present sugar juice in the pith;

b. scraping the pith away from the highly lignified outer rind region including the outer rind fibers, epidermis, and wax of the stalk while retaining substantially all of the naturally present sugar juice in the pith; and

c. adding to the separated pith a dietary supplement for the livestock.

2. The process of claim 1 wherein the dietary supplement includes a nitrogenous protein substitute, a leguminous meal and a mineral mix.

3. A process for producing ruminant livestock feed from sugarcane, the sugarcane having as components a 7 highly lignified outer rind region including outer rind fibers, epidermis and was covering the outer rind region, and an interior of pith containing naturally present sugar juice, which process comprises:

a. splitting sugarcane stalk parallel to a longitudinal axis of the stalk while retaining substantially all of the naturally present sugar juice in the pith;

. scraping the pith away from the outer rind region of the sugarcane stalk including the outer rind fibers, wax and epidermis, while retaining substantially all of the naturally present sugar juice in the pith; and

. adding to the separated pith:

i. a protein substitute comprising from about 1 to about 20 percent urea;

ii. 10 to percent of a meal selected from the group consisting of soybean, clover, peas, peanuts, beans and alfalfa, and

iii. 5 to 50 percent of a mineral mix whereby additional nutrient supplement comprising basic constituents necessary to insure natural growth of the ruminant livestock is supplied.

4. A process for providing livestock with a feed from sugarcane, the sugarcane having as components a highly lignified outer rind region including outer rind fibers, epidermis and wax covering the outer rind region, and an interior of pith containing naturally present sugar juice, which process comprises:

l3 14 a. splitting sugarcane stalk parallel to a longitudinal tially all of the naturally present sugar juice in the axis of the stalk while retaining substantially all of pith; and the naturally Present Sugar .l m the P c. feeding the separated pith containing substantially b. scraping the pith away from the outer rind region of the sugarcane stalk including the outer rind 5 fibers, wax and epidermis, while retaining substanall of the naturally present sugar juice to livestock. 

2. The process of claim 1 wherein the dietary supplement includes a nitrogenous protein substitute, a leguminous meal and a mineral mix.
 3. A process for producing ruminant livestock feed from sugarcane, the sugarcane having as components a highly lignified outer rind region including outer rind fibers, epidermis and was covering the outer rind region, and an interior of pith containing naturally present sugar juice, which process comprises: a. splitting sugarcane stalk parallel to a longitudinal axis of the stalk while retaining sUbstantially all of the naturally present sugar juice in the pith; b. scraping the pith away from the outer rind region of the sugarcane stalk including the outer rind fibers, wax and epidermis, while retaining substantially all of the naturally present sugar juice in the pith; and c. adding to the separated pith: i. a protein substitute comprising from about 1 to about 20 percent urea; ii. 10 to 90 percent of a meal selected from the group consisting of soybean, clover, peas, peanuts, beans and alfalfa, and iii. 5 to 50 percent of a mineral mix whereby additional nutrient supplement comprising basic constituents necessary to insure natural growth of the ruminant livestock is supplied.
 4. A process for providing livestock with a feed from sugarcane, the sugarcane having as components a highly lignified outer rind region including outer rind fibers, epidermis and wax covering the outer rind region, and an interior of pith containing naturally present sugar juice, which process comprises: a. splitting sugarcane stalk parallel to a longitudinal axis of the stalk while retaining substantially all of the naturally present sugar juice in the pith; b. scraping the pith away from the outer rind region of the sugarcane stalk including the outer rind fibers, wax and epidermis, while retaining substantially all of the naturally present sugar juice in the pith; and c. feeding the separated pith containing substantially all of the naturally present sugar juice to livestock. 